Typewriting machine



Jan.3,`193'9. WEHELMOND n M2245 TYPEWRITLNG MACHINE Filed March 9, 1936 2 sheets-#shew 1 Jan; 3, 1939. w. F. HELMOND TYPEWRITING MACHINE 2 Sheecs--Sheei- 2 Filed March 9, 1936 ATTO RNEY Patented Jan. 3, 1939 PATENT OFFICE 2,142,245 TYPEWRITING MACHINE William F. Helmond, West Hartford, Conn., as-

signor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application Marchi), 1936, Serial No. 67.884

14 Claims. (Cl, 197-138) 'I'his invention relates to the work-piece feeding and guiding devices of typewriting machines.

The work-piece is held in yielding contact with the platen by rolls mounted in frames which permit the withdrawal of the rolls. Commonly auxiliary feed-rolls .press the work-piece smoothly against the platen above the printing point.

The auxiliary feed-rolls are usually carried on a bail, which may swing the rolls above and to the rear of the platen to free the work-piece. Or the rolls may be drawn forwardly of the platen, leaving a clear space to permit an introduced work-piece to advance upwardly without manipulation by the operator. v

'Ihe usual mechanism is such that the returning feed-rolls are brought directly downward, and the middle bowed-out portion of a stili workpiece, which does not bend. naturally around the platen, may be struck or fouled by the returning rolls, and creased, or caused to bulge, at the printing point. It has been proposed to bring the rolls to rest forwardly of the platen, and loosely confine the work-piece. Such construction necessitates additional manipulation by the operator to carry the rolls rearwardly and bring the workpiece into printing position.

It is a feature of this invention to provide an auxiliary feed-roll structure in which the feedrolls, when the bail is given a single short pull or impulse by the operator, will swing downwardly from the released position with a radius of rotation suflicient to bringthe feed-rolls to a position in front of the work-piece, and then in a continuing motion without additional manipulation move rearwardly against the platen, drawing the work-piece into proper writing position.

The radius of swing of the feed-roll bail is sufcient to clear the work-piece, regardless of the position assumed by the work-piece when freed 4o by elevating the feed-roll structure.

The feed-rolls are drawn against the platen with sufiicient force to hold'stiif work-pieces or work-packs.

The feed-rolls may be yieldably held forward 45 of the platen, and may be swung upwardly into released position directly from the forward position, or brought from the released position directly to the forwardly-held position.

The side arms of the feed-roll bail are swing- 50 ably and slidably mounted upon the platen-frame.

An overthrow spring swings the side arms forwardly after a portion of the upward swing has been traversed, thus extending the radius of the arc of swing. With. the feed-rolls in the released Q5 position, a short forward pull by the operator will cause them to swing downwardly against the resistance of the overthrow spring, the extended radius being sufficient to bring the feed-rolls outside of the work-piece. One or bothof the side arms may be provided with a cam which, near 5 the completion of the down stroke of the bail, co-operates with a fixed pin or abutment'to direct the bail-structure rearwardly. The rearward motion of the bail, and the accumulatedv momentum thereof, are suiiicient to cause the overthrow 10 spring to pass its dead-centerv position, whereupon the subsequent reaction. of the spring completes the rearward motion of the bail, and brings the feed-rolls into operative position.

Means are also provided to enable the auxiliary 15 feed-rolls to be raised clear of the platen conjointly with casting off the main feed-rolls, to permit adjustment or manipulation of the workpiece. y

This invention also discloses 'a platen-frame 20 having a rear paper-table composed of hinged sections, one of which sections may be swung upwardly to aord access to the usual tabulatorrack. The usual flat tie-bar which spans the platen side plates is replaced by a tie-rod, which 26 additionally serves as the hinge-pin for the papertable'.

It is an object of this construction to simplify the platen-frame by eliminating the short pintles commonly used to pivot a hinged paper-table, and 30 making it possible to form the knuckle of the paper-table hinge with only three intertting sections. The knuckle thus includes a short tongue at each end of the fixed section of the paper-table, and an unbroken, central tongue, 35

wider than the work-piece for which the platenframe is designed, by which themovable section is pivoted on the tie-rod.

Additional advantage may be taken of thislconstruction by forming the usual centering scale 40 on the central tongue, which may be so shaped as to present a pleasing convex surface.

The hinged section of the paper-table may be yieldingly held in normal position against suitable abutments projecting from the platen side plates, the said abutments preferably being padded to prevent the generation of vibratory noises during operation.

Other features and advantages will `hereinafter n appear.

In the accompanying drawings,

Figure 1 is a perspective, illustrating the invention as applied to the platen-frame of an Underwood standard typewriter.

Figure 2 diagrammatically shows the co-opera- 56 tion between the mainl feed-roll-release mecha.- nism and the upper feed-roll bail.

Figure 3 is a perspective, illustrating the assembly of the bail-operating mechanism at the right-hand side arm.

Figure 4 illustrates the position of the feed-roll bail when rthrown back completely out of use.

Figure 5 shows the direction of the line of action of the spring after the bail side arm has been directed rearwardly on the return from released position.

Figure 6 is a sectional view of the platen-frame of Figure 1, additionally showing the .carriageframe and supporting members.

Figure 7 illustrates the path taken by the feedrolls on returning the bail ,from released to operative position.

Figure 8 diagrammatically illustrates the extension of the radius of rotation of the feed-roll bail when being swung upwardly into released position.

Figure 9 illustrates the bail drawn forwardly into position for erasures or work-sheet manipulation.

Referring to Figure 6, a carriage-frame |5 of an Underwood typewriter runs upon front and rear rails |6, |1, supported by standards of the machine-frame.

'I'he carriage has a platen-frame 24 case-shiftable by the usual shift mechanism, which, because of familiar design, has been omitted from the drawings in the interests of clarity. Figure 6 shows the frame in the lower-case position, with a stop |9, secured to platen-frame side plates 26 resting on a shoulder 2| of a clamp 22 which secures a case-shift fulcrum-rod 23.

A rear paper-table is formed of hinged sections 26, 31, the hinge-pin being a tie-bar 28,

` Figure 6, of substantial strength, spanning and n re-enforcing the said side plates 26, and secured thereto by screws 29, the right-hand screw being shown in Figure 1. A platen 3@ is journaled in the side plates on an axle 3|, with the usual knob (not shown) provided at the end thereof to afford means for manual rotation of the platen.

'I'he front section 21 (Figure 6) of the papertable has an apron 33 curving around the bottom of the platen to direct a work-piece 34 between the platen and releasable main feed-rolls 35, 36 and up into printing position above the wingscales 36, at which types 31 print. Arms 39, 46 support spindle-rodsv 4|, 42 for the main feedrolls 35, 36, said arms extending respectively forwardly and rearwardly from a common fulu crum-rod 43, supported at its ends by the platenframe side plates as at 44, Figure 1. Springs acting upon the arms 39, 46, serve to press the main feed-rolls 35, 36 against the platen.

For rocking the main feed-roll-carrying arms 39, 46 jointly about the common fulcrum-rod 43, to withdraw and thereby release the main feedrolls from the platen,.the mechanism includes a cam-shaft 46, journaled in hangers 41 (Figure 1) depending from the fulcrum-rod 43. Cam-shaft 46 has camming flats 48, Figure 6, which may coact with arms 56, 5|, connected respectively to the main feed-roll-spindle-supporting arms 39, 46. Any suitable number of pairs of the main feed-rolls 35, 36 may be provided, and all may-be operable from the common cam-shaft 46. A manually-operable feed-roll-release lever 52, Acomprising an arm 53 (Figure 6) provided with a finger-piece or handle 54 and a second arm 55, is pivoted upon a fulcrum-stud 5'6 extendingfrom one of the side plates 26. said arms having a common hub. The arm 66 may be connected by a link 51 to a crank 56 of the feed-roll-releasing cam-shaft 46.

Upper feed-rolls 66, Figure 1, which yieldingly hold the work-piece against the platen 36. may be slidably mounted to rotate on a shaft or rod 6|. The rod is removably secured, as by screws 62, to side arms 63, 64, the forward ends of which, turned in at iight angles as shown, form means of rigidly supporting the rod 6| The rod and side arms form a bail 66 of substantial strength. The three parts of the bail may be completely finished as to plating, polishingl etc., before assembly, and the component parts, including the rolls 60, are easily replaceable.

At the rear ends thereof, the side arms 63, 64 are formed with a head-portion 61, in which a longitudinal slot 68 is cut. Intermediate the slotted portion, the heads 61 are provided with a tongue 16, which near its end is provided with a headed pin 1|.

A rock-shaft 12 is Journaled in the side plates 26 above and to the rear of the platen v36, the `said shaft passing through the slots 66 of the side-arm heads 61. At the right-hand end, the shaft 12 is formed with milled flats 14 (Figure 3), and a crank 15, formed with a hole shaped to cooperate With the flatted end of shaft 12, is thereby held on the said shaft against independent rotation. The crank 15 is mounted outside of the right-hand side plate, and may be removably secured to the shaft 12 by a screw 16.

The shaft 12 is of sufllcient length to provide for slight manufacturing discrepancies in the overall width of the platen-frame, the end 12* oi the said shaft projecting through the left side plate 26, as shown in Figure 1.

The bail side arms 63, 64 are swingably and slidably'held between washers 11, Figure 1, and forked cranks 18, the said cranks being mounted on the shaft 12 and securely held adjacent the side arms as by the set-screws 66. The pins 1i of the tongues 16 extend to work within the forked end of the corresponding crank 16. 'I'he shaft 12 is held against excessive sideplay by the co-operation of the forked cranks 16 and the crank 15.

Forward of the tongue 16, the left side arm 63 is formed with an extension 6|, Figure 5, having a rearwardly and downwardly sloping cam-surface 82 to coact with a pin 63 projecting inwardly from the left side plate 26, as later described.

A tensile spring 64 is anchored, below the center line of the rock-shaft 12, on a suitable pin -or screw' 85 projecting from a lug 66 extending downwardly from the right-hand side plate 26. The pin 65 may co-operate with a screw 61 in securing the case-shift stop I9. The forward end of the spring 84 is hooked around a pin or stud 88 projecting from the crank 15, the said pin being formed with a groove or slot to receive the spring. The spring 64 and the crank 15 preferably underlie the flanged surface 69 of the side plate 26, and may be concealed from view by the customary sheet-metal' mask (not shown) with which the side plates 26 are customarily provided.

The crank 15 and the forked cranks 16 are so placed on the shaft 12 that when the feedrolls 66 are in operative position, as seen in Figure 6, the stud 88 of the crank 15 is below the center line of the rock-shaft 12, and the spring 64 thereby f urges the shaft 12 in a rotation clockwise of Figure 6, causing the forked cranks 16 to draw the side arms 63-64 rearwardly to the extent of the slots 68.

Lifting the bail 66, preferably by an upward finger-pressure on the under side of the rod 6i, causes a rotation of the rock-shaft, counterclockwise of Figure 6, through the co-operation of the pin-and-slot engagement of the forked crank 18 vand the tongue 10. The corresponding movement of the crank 15 places the spring 84 'under increasing tension. After a partial upward swing of the bail, as shown diagrammatically in Figure 8, the crank 15 will have brought the line of action of the spring 84 above the center line of the rock-shaft. The immediately following reaction of the spring 84 causes the rock-shaft 12 to rotate sharply, and again through the co-operation of the forked crank 18 and pin 1l at each side arm the said arms are thrown or kicked forward to the full extent of the slotted heads 61, and the arc of upward rotation of the bail is consequently increased in radius, as represented in the dotted line in Figure 8. The side arms come to rest in the released position, Figure 8, against a gaging pin 90 projecting from the right side plate 20.

By giving the feed-roll rod 6| a quick, forward, flip or pull, the feed-roll bail 66 may be returned from the released position to operative position in a continuous motion, the novel path taken by the feed-rolls being indicated by dotted lines in Figure 7. The force of the pull to start the bail-movement need only be great enough to `overcome the resistance of the spring 84, which,

. when the feed-roll bail is in the released position,

is not large, and to give tothe bail-structure a slight momentum. The weight of the bail-structure, as it passes the vertical position, adds to the force of the descent, and aids in overcoming the increasing tension of the. spring 84.

As shown in Figure 7, the arc of travel is at maximum radiusuntil the cam 82 strikes the pin 83. The slope of the cam directs the side arms rearwardly, causing the rock-shaft 12 to continue to rotate, until the crank 15 brings the spring 84 below the centerline of the rock-shaft, as shown in Figure 5, whereupon the action of the spring, operating through the forked cranks 18, pulls the side arms 63, 64 rearwardly to the home position. The extended radius of side arms 63, 64 during the larger portion of the downward travel of the bail is suiiicient to bring the feed-roll rod 6| outside of the work-piece 34, as shown in Figure 2, and the subsequent rearward movement of the bail draws the work-piece smoothly against the platen. In addition, the upper feed-rolls 60 tend to ride up on the platen, thus acting to iron out the work-piece. y,

It will be obvious from Figures land 8 that the arrangement is such that the feed-roll, in moving to its cast-off position above the platen and in its restoring movement, takes an orbital path in which the return movement is substantially forward of the path of casting off movement, in order that the returning feed-roll does not foul the looose end of the work sheet.

The action of the spring 84, in constantly urging the feed-roll bail into rotation against the platen, provides for continuous compensation for wear of the upper feed-rolls 60.

'Ihe feed-roll bail may be drawn forwardly from the operative position to a position shown in Figure 9, in which the feed-rolls 60 are brought clear of the work-piece 34 to facilitate the insertion of a new work-piece, or when making erasures. The forward ends 65 of the side arms 63, 64 may be formed with upwardly and rearwardly curving extensions 9| vwhich form convenient handles with which to draw the feed-roll bail forwardly. The bail may be latched in the forward position by engaging the pin 83 in a detent-notch 92 formed in the cam-extension 82. As indicated in Figure 9, the forward movement of the bail 66 will, through the (5o-operating pins 1l and forked cranks 18, rotate the shaft 12 to a point at which the face of the spring 84 is applied Vabove the rock-shaft 12, and thus the side arms will be yieldably held in the desired position. To return the feed-rolls 6U to operative position, the operator need only push on the feed-roll rod 6I, and the crank 15, being again rotated to a point below the shaft 12, will cause the spring 84 to pull the rolls against the platen.

To bring the feed-roll bail from the released position of Figure 8 to the position of Figure 9, the operator need only retain control of the bail, bringing it down more slowly, and -latching the notch 92 into engagement with the pin 83. The detent-notch 92 is expressly madeA Asufficiently shallowto permit the operator to swing' the bail from the position of Figure 9 to the position of Figure 8 by a light upward pressure applied beneath the feed-roll rod 6I. TheVbail-structure may also be swung upwardly to a position of complete disuse, as in Figure 4, in which itjmay be held by pressing the bail-structure downwardly by the pin 90.

the force of the descent.

430 so that a shoulder 93 of the side arm `64 is held f The upper feed-roll bail 66 may also-bel lifted i' to raise the top feed-rolls 60 off the platen conjointly with casting off the -main feed-rolls 35,L 36 through the co-operation of a stud 94, Figure 2, provided on the link 51 of the main feedroll release, and an extension formed on the right-hand side arm 64. The stud 94 is operative, as shown in Figure 2, to raise the bail 66 at operation of the main feed-roll-release lever 52the full depression of which rotates the camshaft 46 to its fully operative feed-roll return checking position, causing the feed-rolls 35, 36

to be swung clear of the platen and held in re- A leased position. The bail 66 is consequently held in released position. The top and bottom feedf f rolls may be returned to operative positionby an upward movement of the lever 52, or by press-y 1. I I

5,5 makmg adjustments of the work-piece position, 5

ing down on y,the upper feed-roll bail 66. For' feed-rolls on through the co-operation of a ramp 96, Figures 1 and 6, at the rear of the extension 95, which, by engaging the stud 94, cams the link 55 downwardly, and thus actuates the main feed-roll-release mechanism.

In the foregoing description, and the drawings applicable thereto, the camming extension 8| has been shown only on the left-hand side arm 63 of the bail 66. However, for wide-carriage machines, it may be desirable to include such a camming device on the right-hand side arm 64, to= preventl any possibility of distortion as the bail-structure is being swung into operative position.

The two sections 26 and 21 of the rear papertable 25 may be considered as being the leaves of a hinge, the tie-bar 28, which serves primarily as a re-enforcing member for the platen-frame 24, forming the hinge-pin. 'I'he knuckle of the hinge may include narrow tongues at the ends of the section 21, the said tongues curving around the tie-bar 28, as shown in Figure 1.

-The rear section 26 is pivotally secured to the tie-bar by a tongue |02 also curved around the said bar. The Width of the tongue |02 is greater than the width of the work-piece for which the platen-carriage is designed, and on the unbroken surface of the tongue |02 a centering and linegaging scale |03 may be imprinted. A transverse groove |04 may be pressed into the rear section 26, the said groove being substantially parallel to the tie-bar 28, and acting to form, with the downward sweep of the tongue |02 where it curves around the said tie-bar, an attractive convex surface which imparts Aa maximum of legibility to the graduations of Vthe scale |03. It will be seen from Figure 1 that the operators view of the scale is not obscured by the feed-roll bail rock-shaft 12.

At each end of the section 26, a flange |06 is turned downwardly as shown in Figures 1 and 6, to strengthen the said section, and to serve as a support for a side-gage-supporting rod |01. Springs |06, coiled around the tie-bar 28 at each end of the platen-frame, have one end anchored vin a hole ||0 in each side plate 20, and the other end hooked into the flange |06, as shown in Figure 1. The springs |00 act to rotate the section 26 downwardly about the tie-bar 28, and hold the said sections yieldingly against upwardly oifset tongues of a pair of lugs ||2 extending inwardly from each end plate 20. The tongues are preferably padded, as by the felt ring H3, to eliminate the production of vibratory noises during operation.

A side gage IH, of familiar design, is mounted on the rod |01, so as to be slidable across the paper-table section 26. As clearly indicated in Figures 1 and 6, the forward edge of the side gage ||4 curves into the groove |04, and thereby extends into close proximity With the scale |03, but does not rub across the graduations thereof. The position of the side gage is thus clearly designated by the scale, and thelatter remains free from the possibility of defacement by the side gage, regardless of the number of times the side gage is shifted by the operator to center or gage the position of the work-piece with respect to the platen.

As shown in Figure 6, the typewriter may include'a tabulator-rack ||5, of familiar design,

supported on the carriage-frame I as by a strap As indicated by dotted lines in Figure 6, the rear portion of the paper-table may be swung forwardly to permit access to the tabulator-stops ||1, and the scale |20. Y

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewritingmachine, the combination with a platen and a platen-frame, of a feed-rollcarrying bail, a rock-shaft in said frame, the said bail having side arms pivotally mounted on and radially movable relatively to said rock-shaft, the said side arms being operatively associated with the rock-shaft by a crank and pin connection, an overthrow spring-device'acting upon said rockshaft to cause radial movement `and thereby an automatic change inthe radius of rotation of the bail side arms when the bail is swung upwardly of the platen, and means including a cam-device on one of the'side arms of the said bail to direct the bail rearwardly on the return of the feedrolls to operative position, the rearward motion of the bail enforcing a rotation of the said rockshaft suicient to cause the overthrow springdevice to complete the rearward movement of the said bail.

2. In a typewriting machine, the combination with a platen and a platen-frame, of a rotatable shaft in said frame, a feed-roll-carrying structure connected to said shaft for rotating therewith and moving radially thereof, and an overthrow spring connected to said shaft to rotate the latter in opposite directions and concomitantly move said structure radially in opposite directions.

3. In a typewriting machine, the combination with a platen and a platen-frame, of a feed-roll bail adapted to swing about an axis and to move radially of said axis, and a device coacting with said bail to automatically move the .bail radially in response to a swing of the bail either to or from the platen about said axis.

4. In a typewriting machine, the combination Awith a platen and a platen-frame, of a top-feedroll bail, a rotatable mounting for said bail in said frame, said mounting and bail being connected so that the bail may rotate with and move so that the roll-bearing rod may be drawn forwardly ofthe platen or swung upwardly into a released position above the platen, and a device acting upon said side arms, in response to upward swing thereof, to move said arms radially to cause an automatic change in the radius of rotation of the bail. 6. In a front-strike typewriting machine, the combination with a platen and a platen-frame: of a feed-roll bail comprisng a roll-bearing ro'd extending longitudinally of said platen and side arms having outer ends spanned by said rod, said side arms extending rearwardly to an axis of swing behind the platen, and adapted to swing and to move radially of the axis of swing, the said roll-carrying rod thus being capable of be- Vwith the feed-rolls against the platen, without manipulation by the operator.

7. In a typewriting machine, the combination with a platen and a platen-frame, of a pivotally` mounted bail having a front rod carrying a feedroller co-operative with the top of said platen, and a device acting automatically, toy give the said bail an increased radius of rotation, in response to swinging the bail upwardly off the platen, said device being arranged to control the bailf'so that as the bail is returned toward operative position, the increased radius is retained over a portion of the return travel and is then normalized to bringthe said bail into operative l position.

8. In a typewriting machine, the combination with a platen and a platen-frame, of a top-feedroll carrying bail, arranged to swing about and move radially of an axis behind the platen, a device acting automatically, to move said bail radially and thereby give said bail an increased radius of rotation, in response to swinging vthe bail upwardly oif the platen, and a camming device operative upon said bail and coacting with said rst mentioned device to move the bail radially toward the platen after a certain portion of the return movement of the bail at the increased radius has been traversed.

9. In a front-strike typewriting machine, the combination with a platen and a platen-frame, of a feed-roll, a supporting structure therefor in said frame and having a fulcrum behind the platen, whereby the feed-roll is swingable upwardly in a certain path from a position on the platen above the printing line, said structure being adapted for returning the feed-roll in a different path forwardly of said upward path and eventually back to said position, and a device adapted to co-operate with and govern said structure automatically to determine automatically, and consonantly with the upward swing and return of said feed-roll, said different upward and return paths. 1

10. In a. front-strike typewriting machine, the combination with a revoluble platen and a platen-frame, of a bail pivotally mounted so as to be swingable at a variable radius about an axis behind the platen, said bail mounting a feed-roller co-operative with thesaid platen at a position above the printing line, means acting automatically` to give the said bail an increased radius of rotation in response to swinging the bail upwardly oi the platen, and a cam on the bail and arranged to engage with anabutment on-said platen-frame when the feed-roll bail is swung downwardly, whereby the radius of rotation will be so shortened as to direct the feedroll rearwardly toward said position against the platen, said means being adapted to move said bail radially to bring the feed-roll nally to said posit-ion in response to the engagementof said cam with said abutment.

11. In a front-strike typewriting machine, the combination with a platen and a platen-frame, of a bail pivotally mounted so as to be swingable at a variable radius about an axis behind the platen, said bail mounting a feed-roller co-operativewith the said platen at a position above the printing line, a device and an overthrow-spring governing said device for automatically giving the said bail an increased radius of rotation in response to swinging the bail upwardly off the paten, and a camming device associated with the said bail to direct the bail rearwardly against the paten after a portion of return movement of the bail at the increased radius has been traversed, the said rearward direction of the bail by said cam-device causing said overthrow spring to govern said device to complete rearward radial movement oi the bail and thus to draw the feedroll against the platen.

12. In a front-strike typewriting machine having a platen-frame, a platen journaled therein, a main feed-roll co-operative with the under side of the platen, a controller shiftable oppositely to cast off and restore said main feed-roll, a swingabiy and radially movable bail mounting an upper feed-roll, said bail being capable of being moved radially to a position to draw the upper feed-roll forward of the platen and being yieldably held insaid position, an operative connection between said bail and controller whereby the said bail may be swung to lift the upper feed-roll clear of the platen conjointly with the casting off of the main feed-roll by said controller, said connection being adapted so that if the main feed-roll and controller are moved to casting off position while the upper feed-roll is in the aforesaid forwardly drawn position, the upper and lower feed-rolls may be conjointly returned to operative positions by means of said connection by pushing rearwardly against the upper feed-roll.

13. In a front strike typewriting machine, the combination with a revoluble platen, of a top feed-roll to hold a work-sheet above the printing point against the platen, a bail for said roll, supporting means for said bail adapted to permit said roll to be moved forwardly from the platen and back, or to be raised from the platen and lowered from said raised position to a position in front of said platen, and a spring-device acting automatically to cause the path of said roll when lowered to be forward of the path in which it is raised.

14. In a front strike typewritenthe combination with a revoluble platen and a top feed-roll or the like to hold a work sheet to the platen above the printing line, of means mounting said feed-roll for movement to a cast-ofi'v position above the platen and for restoring movement, and a device coacting with said mounting means to direct automatically the casting oil and return movements of said feed-roll in an orbital path, so that automatically the return path of movement is caused to be substantially forward of the casting-off path of movement of said feedroll, whereby at the return of the feed-roll the latter does not foul the loose end of said work sheet. 

